The 12V battery is the low voltage battery on your Tesla electric model 3, whatever the model. It is different from the main battery pack that powers your Tesla. This low voltage battery is responsible for peripheral functions such as powering the headlights, internal lights, entertainment system, looks car windows, and so on.
Earlier Tesla model 3s were shipped with lead acid 12V batteries while newer ones come with the lithium ion 12 Volt battery. The lead acid 12-volt batteries are notorious for needing constant change. So, if you are having to change the 12 Volt battery on your Tesla model 3 regularly, then it is likely that yours is lead acid. If, on the other hand, you do not experience frequent issues with your 12-volt battery, then it is likely that yours is lithium ion.
Ideal Replacement Type
When looking to replace the 12 Volt battery on your Tesla model 3, the first thing to bear in mind is that using a lead acid 12V battery as a replacement is out of the question. Lead acid batteries are unreliable, and they are not durable. Here’s why:
- The best-quality lead acid batteries have at most 1000 cycles in them before they start to degrade rapidly
- They should never be below 50% charge to maintain healthy lifespan
- They need constant maintenance like watering and corrosion cleanup
- They have 33% self-discharge per month
Add these up and you find that you have to replace the lead acid battery every 1.2 years or so. And that’s with normal use.
Compare and contrast this with lithium-ion batteries:
- They have more than 5000 cycles in them before they begin to degrade
- Zero maintenance is needed
- 100% of the charge can be used with no issues
- They have 2% self-discharge per month. You only need to make sure to disconnect the battery if you will not be using your Tesla for extended periods.
Therefore, in this article about the best 12 Volt battery for Tesla, I will only be considering lithium-ion batteries. And if you currently have a lead acid 12V battery, your best bet is to make the switch and get a reliable lithium-ion battery
Best 12V Batteries for Tesla
This list is based on an exhaustive test for reliability, cost-effectiveness, output, durability, and accessibility.
- Reliability: Lithium-ion batteries should be reliable by default. That’s why they’re recommended in the first place. You want a battery that you can always rely on to perform its functions every time you use your Tesla. Some lithium-ion batteries have been known to charge poorly, while others get out of the cool state slower than normal. The batteries in this list have been tested to always perform optimally over a reasonable period.
- Cost: Obviously, you do not want a secondary battery to cost an arm and a leg. The main battery pack is quite expensive already. The batteries on this list have the right balance of quality and cost, making them cost-effective.
- Output and Performance: A 12V battery must supply at least 12V. But, many top-quality batteries supply more than that. There are two reasons for this:
- With the extra volts, the life span of the battery is marginally increased. This means that, under normal conditions, the batteries will last longer than the average 12V lithium-ion battery
- The extra volts will also guarantee that the battery is able to power every required component on Tesla model 3s, no matter the model, model year, or configuration
- Durability: A standard Lithium-ion battery should last at least 5 years on a Tesla. Anything less is not acceptable…unless, of course, you are not following recommended best practices for Tesla battery care. You can find those best practice recommendations here under the Charging Habits section.
- Accessibility: What good is a product if it’s hardly available or hard to access? The batteries in this list can be easily bought on Amazon, which is pretty much accessible to everyone? The batteries in this list can be easily bought on Amazon, which is accessible to pretty much everyone.
1. Ohmmu 12V Battery for Tesla Model 3
There’s a reason why this is the most popular and trusted 12V battery for Tesla. It ticks most of the boxes in the criteria listed above.
Here are some of the key specifications:
- 12.8V output
- 156Ah (amp hours)
- Prismatic-LifePo4 cell type. What it means? Better long-term capacity and more energy.
- Up to 5000 lifecycles under average conditions of use
- Built-in Battery Management System
The difference is immediately noticeable when you use an Ohmmu 12V battery for Tesla. Much better sound system quality. Very little power drain, no matter for how long you leave your Tesla. Zero incident for years and years.
- Long-lasting and always reliable
- Powerful output for all model 3 components
- Deep cycle and minimal drain or leakage
If you are using a Tesla model 3, you may struggle to find an Ohmmu 12V battery as at the time of writing this article. It is out of stock both on the manufacturer’s website and on Amazon. But, don’t let that put you off.
Most 3rd-party outlets have these batteries, and you can easily get one from your local dealer. Ohmmu have promised to come back with upgrades in a short time, so you may even find one rather easily on Amazon by the time you read this article.
Their model 3 12V batteries seem to have compatibility issues and many users have had to get theirs replaced by the manufacturer.
There is a conspiracy theory that Tesla keeps pushing out updates to undermine the compatibility of Ohmmu batteries with Model 3, but I think that what’s more likely is that Ohmmu have just a little bit more work to do to get it working properly.
- Because the same issue does not occur with Ohmmu 12V batteries for Model S and X. And those are readily available on the manufacturer’s website and on Amazon.
- And because the compatibility issue mostly happens only when you have aftermarket electrical and electronic components installed in your Tesla model 3.
You can get an Ohmmu 12V battery for your Tesla model 3 here.
2. EarthX ETX900 Lithium-Ion Battery
Perhaps, almost as popular as the Ohmmu 12V battery for Tesla model 3 is the EarthX ETX900 lithium-ion battery. Although you will not find an EarthX lithium-ion battery specifically designed for Tesla model 3s, the EarthX ETX900 which is designated for experimental aircraft is an exact fit for any Tesla model and model year.
And, unlike the Ohmmu 12V battery, the EarthX ETX900 12V experimental aircraft battery does not have the compatibility issues with any Tesla model or model year.
Here are some key specifications:
32 amp hour
- 13.2 volts
- 760 cold cranking arms
- 1600 peak cranking Amps
- LIFE PO4 cell type
- Enhanced overvoltage protection of 100+ volts
- Easier to recharge the battery in the over discharged protection mode
- Enhanced short circuit protection
- Excellent compatibility with Tesla and Tesla aftermarket components
- Faster 13.2 volt resting voltage
I have yet to find any comms with this product
2. WPS HJ04L-FP-IL Featherweight Lithium Battery
This product from Western Power Sports is not as well-known as the two above, but it stands up to them in every department. From personal tests and user reviews, the WPS HJ04L-FP-IL is arguably the most versatile of them all.
- Powerful, versatile, reliable, and very affordable
- No meaningful con with this product
These are the three brands that fit our criteria as listed above. That’s not to say that there aren’t other brands that may get the job done, but I am yet to find any that perform like products listed above.
Replacing the 12V Battery
I have included this here because getting a replacement 12V battery is one thing, but installing it is another matter. And you will need this guide whether you are doing DIY replacement or having a technician install it for you.
You want to make sure that the installation is done following best practices as recommended by Tesla. Failure to do this can result in harm to humans, damage to electronic and electrical components, as well as to the entire power system in your Tesla.
Refer to this guide from Tesla to replace the 12V battery as applies to you. The guide contains text, pictures, and videos that are easy to follow.
When considering replacing your 12V battery, you are likely to want to know how much the entire project will cost. I did an article on 12V battery for Tesla replacement cost.